FR2890710A1 - HOLLOW SHAFT FOR TORQUE TRANSMISSION AND METHOD FOR MANUFACTURING THE SAME - Google Patents

Abstract

According to the invention, the shaft is characterized in that the hollow shaft may be composed of or composed of two components, one of which contains a shaft portion and the profile (2, 3), and on the side opposed to the profile of the shaft an outer profile (2, 3), transmitting the torque, of an interlocking assembly, and the other component being a bushing-type component with the second profile and an inner profile, transmitting the torque, of an interlocking assembly (5, 6).

Description

2890710 1

  The present invention relates to a hollow shaft which is provided with external profiles provided on both ends for the transmission of torque, such as longitudinal toothings, V-belt teeth, polygonal profiles or the like, the interspersed shaft areas having smaller diameters than profiling.

  Such hollow shafts may be used for driving assemblies, for example oil pumps, the latter with the central portion being narrower for reasons of space than the ends on which the teeth are unscheduled.

  A proposal to manufacture such trees goes beyond making these one-piece trees by cold extrusion. In this case, one of the profilings should be expanded after the hollow shaft area has been manufactured. Such enlargements can only be made in very complicated special tools and therefore require a significant proportion of the complementary work. As a result, significant additional costs are incurred.

  The object of the present invention was to create a hollow shaft of the type mentioned at the beginning which is characterized by particularly simple, advantageous and fast manufacturing as well as by high precision and also to provide processes for its advantageous, rapid and precise manufacture. .

  According to the invention, this result is obtained with a hollow shaft of the type indicated at the beginning by the fact that this hollow shaft can be assembled or assembled from two components, one of which contains the hollow shaft section and which contains a profile, and on the side, opposite the profile, the shaft an outer socket assembly and transmitting the torque, and the other component being a sleeve-shaped component with the second profile and an inner profile and transmitting the couple of an assembly by interlocking.

  In the present case, it is advantageous that the shaping of the hollow shaft-shaped part, the profilings, and a profile of the interlocking assembly of one component and / or the shaping of the other component by cold extrusion from a massive blank.

  It may be useful in the present case to provide a tight fit between the inner and outer profile of the interlocking assembly, so that after the sleeve is engaged during transport, handling and assembly, the it can not fall into the tree-shaped part.

  When the two profilings provided on the shaft ends are provided with different diameters, it is advisable that the smaller profiling be provided on the sleeve-shaped component and the larger profiling be made in one piece with the shaped part. tube shape.

  For the manufacture of the hollow shaft portion with profiling designed on one of its ends with a diameter greater than the shaft diameter and transmitting torque, 2890710 3 as a splined shaft profile and an outer profile, transmitting the torque and provided on the opposite shaft end, an interlocking assembly, it is advantageous to provide at least some of the process steps mentioned below: a) cutting a blank of material from a bar material, b) a first stamp, the manufacture of a hollow bowl-shaped area with a solid base and the bowl area corresponding at least approximately to the inner diameter and the outside diameter of the part. c) a second stamping, an extension of the hollow zone from the base by cold extrusion, d) perforation of the bottom of the bowl e) extrusion tubes, the beginning of the manufacture of the body of a hollow fiber is effected by cold extrusion, f) a first reduction of the diameter and the wall thickness and an extension of the hollow shaft portion according to step e) and the formation of a zone of collar thickened with respect to the outside diameter of the hollow shaft following the zone provided for forming the cold extrusion profiling, g) a second reduction at least approximately from the ring-shaped zone and an extension of the hollow shaft portion according to step f) by cold extrusion, h) final cold extrusion pressing of the profile area in the form of the external toothing 2890710 4 by the introduction of a mandrel into the inner contour of the profile zone with an identical diameter, a ring-shaped punch and surrounding the mandrel penetrating into the front zone of the end zone and then pushing material into the toothing of a matrix placed around it the area intended for the formation of the toothing, in the event of formation of an axial projection, i) optionally at the same time as step h), the production of the outer profile of the assembly by interlocking in the zone, opposite to the profile zone , hollow shaft by cold extrusion, j) turning of the projection.

  For the manufacture of the sleeve with an external profiling and an inner profile of an interlocking assembly, at least some of the process steps mentioned may be particularly advantageous: a) cutting a blank of material from a bar material b) stamped and at the same time formation of the inner profile of the interlocking assembly, preferably to the final profile dimension by cold extrusion, c) perforation of the bottom, d) turning of the outer diameter, e) manufacturing the outer profile by cold extrusion, a mandrel with a profile corresponding to the inner profile of the interlocking assembly being introduced into the same element and an annular shaped punch, surrounding the mandrel, penetrating into the front zone opposite to the perforated bottom and the material is then pushed back into the toothing, previously placed around the zone provided for the formation of the outer profile, a matrix, an axial projection being formed, f) turning the sleeve height to reach the final dimension, thus removing the axial projection.

  For the subsequent manufacture of a hollow shaft, at least three of the steps mentioned below may be particularly advantageous before or after nesting or insertion of the bushing on the shaft by means of the interlocking connection. .

  a) turning the area inside the profiled zone made in one piece with the shaft profile as a bearing seat, b) making a notch in the outer end zone of the profile, c ) making a chamfer at the beginning of the inner contour in the profile zone, d) making a free cut in the end zone of the cylindrical inner contour in the profile zone.

  In the present case, it may be advantageous to carry out a heat treatment or a surface treatment between certain process steps, in particular softening annealing, so that the material, the structure of which has been consolidated by forming with in the preceding steps, will be softened again, for example during the manufacture of the hollow shaft body with the first profile formed between steps b) and c), d) and e), e) and f), f ) and (g) as well as (g) and (h); during the manufacture of the sleeve between steps d) and e).

  With the aid of Figures 1 - 19, the invention is explained in more detail.

  In the present case, FIG. 1 shows a hollow shaft according to the invention or a hollow shaft manufactured according to an inventive method. FIGS. 2 to 19 show the various steps of the method for producing a shaft according to FIG.

  The oil pump shaft 1 according to Figure 1 is designed as a hollow shaft and has on its ends external profiling in the form of shaft profiles or longitudinal teeth 2, 3.

  Between the two profile zones 2, 3 is a tubular part 4, which has at least partial areas a smaller diameter than the profiles 2, 3.

  The profile 3 and the tubular portion 4 are designed in one piece or in one part in the present embodiment and on the end, opposite the profile 3, of the shaft, the sleeve 7, which carries the profile. 2, is engaged by means of a torque-transmitting coupling assembly 5, 6, which will be described further below. The interlocking assembly 5 and 6 is designed as a snug fit. Both the tubular portion 4 and the profile portion 3 thus formed in one piece as well as the sleeve 7 are manufactured by cold forming, as explained below, at least with respect to its functional areas.

  In the present case, Figure 2 shows a blank 8 separated from a bar material by cutting, here sawing.

  From this blank, part 9 according to Figure 3 is manufactured in an operation referred to as "stamped I" in a cold extrusion process.

  In an operation referred to as "stamped II", the sleeve-shaped portion designated 10, according to FIG. 4, is manufactured by cold extrusion.

  In a "perforation" operation the bottom 11 (see FIG. 4) of the sleeve-shaped component 10 is removed, so that a component 12 is formed according to FIG. 5, which then has no bottom.

  In a process step referred to as "extrusion of the tubes", material is discharged essentially from the zone 13 according to FIG. 5 and the hollow zone 14 of the component 15 according to FIG. 6 is manufactured.

  In the working step designated by "reduction I", the hollow shaft region 16 of the component 17 according to FIG. 7 is manufactured essentially from the zone 14 according to FIG. 6. In the present case, also a zone of col 18 is formed following the zone provided for the formation of the profile 3.

  In a subsequent work operation, which is referred to as "reduction II", the portion designated herein as 16 is shrunk by cold extrusion at least approximately from the neck-shaped zone 18 according to FIG. 7 and zone 2890710. hollow shaft 20 of a component 21 according to FIG. 8 is generated.

  In the process step referred to as "final pressing", component 22 according to FIG. 9 is manufactured with outer profiling 3, which is much more visible in FIG. 10, which shows an enlarged extract X of FIG. the same operation can be formed on the ends, opposite to the toothing 3, of the hollow shaft area 23 the profiling 5, that is to say a polygonal edge for a torque-transmitting coupling assembly. This detail is represented in an enlarged scale in FIG. 11, which shows a section along the line XI of FIG. 9.

  The profiling 3 is formed by the fact that a matrix equipped with a counterprofilage is placed around the zone designated by 19 in FIG. 8, a mandrel is also introduced into the inner contour of the zone 19 and a ring-shaped punch. - partially shown in FIG. 10 and designated by 25 - moves towards the end face 26 (see FIG. 8), enters the zone 19 and delivers the material in the toothing of the die, so that the toothing 3 is formed. In the present case, a projection 27 is also formed, as can be seen in particular in FIG.

  The projection 27 is turned in the process "turn length" on the line 28 according to Figure 12, so that the hollow shaft is formed then with its zone 4 and the tooth zone 3 provided in one piece on and the outer profile 6 of an interlocking assembly, as shown in FIG.

  The manufacture of the sleeve 7 with the outer profile 2 and with the outer profile 6 of an interlocking assembly is shown in FIGS. 13 to 19.

  With the working step referred to as "sawing", a blank 30 is formed according to FIG. 13.

  In the "stamped" work process shown in Fig. 14, a dish-shaped component 31 is made with a cylindrical area 32 and a bottom 33. In the process step shown in Fig. 14, also the profile The inside of the torque transmitting interlock assembly is manufactured as a polygonal ridge by the cold extrusion process step shown in FIG.

  The profiling 5 is clearly visible in FIG. 15, which shows a view from the direction of the arrow XV-XV in FIG.

  In the work process represented by "perforation" according to Fig. 16, the bottom 33 (Fig. 15) is partially removed.

  In the working step referred to as "turning 1" according to Fig. 17, the outer diameter 34 of the sleeve-like component 7 is lathe-shaped.

  In the working step according to Fig. 19, which is referred to as "gear reduction", the profile outer profile 2 is generated substantially identically as profile 3 in the process step according to Fig. 9.

  Also in the process step, in which the sleeve 7 according to Figure 19 is provided with the toothing profile 2, a mandrel corresponding to the profile 5 is axially input into the profiling 5 and a punch 35 in the form of a ring abuts against the face front 36 (FIG. 18), the material coming from the front zone being supported by cold extrusion in a matrix placed around the cylindrical outer diameter 34, which has the opposite shape of the profiling 2, in this counter-profiling, so that a projection 37 then caused is removed 19 in a work process "turning 2" according to Figure 19.

  Before or after assembly of the components 4 and 7, the zone 38, which can serve for example as a bearing seat, can be formed by turning, a notch 39 can be rotated in the outer end zone of the profile 3, in the same way as a chamfer 40 and a clearance groove 41 on the end of the cylindrical zone 38.

2890710 11

Claims (9)

  Hollow shaft with improved profiling provided at both ends for torque transmission, such as splined shaft profiles, interspersed shaft areas having smaller diameters than at least one of the profiles, characterized in that the hollow shaft may be composed of or composed of two components, one of which contains a shaft portion and the profile (2, 3), and on the side opposite the profile of the shaft a profile (2, 3) externally transmitting the torque of an interlocking assembly, and the other component being a socket-like component with the second profile and an inner torque-transmitting profile of an interlocking assembly (5, 6) .   Hollow shaft according to Claim 1, characterized in that the forming of the hollow shaft-shaped part, the profiling and one of the interlocking joint profiles (5, 6) and / or the forming of the other component is made by cold extrusion from a blank (8) mass.   Hollow shaft according to claim 1 or 2, characterized in that a tight fit is provided between the inner profile (2, 3) and the outer profile of the socket joint (5, 6).   4. hollow shaft according to any one of claims 1 to 3, wherein the profiling provided on the ends of the shaft have different diameters, characterized in that the profiling with a smaller diameter is provided on the component ( 14, 17) of the socket type.   Process for the manufacture of a hollow shaft, in particular according to any one of claims 1 to 4, characterized in that a hollow shaft portion is provided with a torque-transmitting profile, designed on the one of its ends with a diameter larger than the shaft diameter, as well as a splined shaft profile and an external torque transmitting profile, provided on the opposite shaft end, of a interlocking assembly, for the manufacture of which at least individual steps are mentioned, mentioned below.   a) cutting a blank of material from a bar material, b) a first stamping, the manufacture of a hollow zone of the bowl type taking place with a solid base by cold extrusion and the zone of a dish corresponding at least approximately to the inside diameter and outside diameter (34) of the profile part, c) a second stamping, an extension of the hollow area (14) from the base being effected by cold extrusion, d) perforation of the bottom of the dish, e) extrusion of the tubes, the beginning of manufacture of the hollow shaft body by cold extrusion, f) first reduction of the diameter and the wall thickness as well as extending the hollow shaft portion and forming a neck area, thickened with respect to the outer diameter of the hollow shaft, following the area provided for formation of the cold extrusion profiling, g) second reduction at least approximately from the shaped area collar and extension of the hollow shaft portion by cold extrusion, h) final pressing of the profile area in the form of the external toothing by introducing a mandrel into the inner contour in the profile area with a diameter identical, an annular punch, surrounding the mandrel, penetrating into the front zone of the end zone and then discharging material into the dentate of a matrix, which is placed in the area intended for the formation of the toothing, with formation of an axial projection by cold extrusion, i) optionally at the same time as step h) producing the outer profile of the interlocking assembly in the zone, opposite to the profile zone, of the hollow shaft by cold extrusion, j) turning of the protrusion.   6. hollow shaft according to claim 5, characterized in that a heat treatment, in particular a softening annealing, is carried out between certain steps, preferably between steps b) and c), d) and e), e) and f), f) and g), as well as between g) and h).   A method for producing a socket with an outer profile and an inner profile of an interlocking assembly, in particular for a component according to any one of claims 1 to 6, characterized by at least some of the following steps.   a) cutting a blank of material from a bar material, b) stamped, in this case at the same time formation of the inner profile of the assembly by interlocking, preferably to the final profile dimension by extrusion cold, c) perforation of the bottom d) turning of the outer diameter, e) manufacture of the outer profile by cold extrusion, a mandrel with a profile corresponding to the inner profile of the interlocking assembly (5, 6) being introduced into that and a ring-shaped punch (2, 5) surrounding the mandrel, penetrating into the front zone opposite the perforated bottom and then pushing material into the toothing of a die, which has been placed around the area provided for the formation of the toothing, then formation of an axial projection f) turning of the sleeve height to the final dimension, then removal of the axial projection.   Process for the manufacture of a hollow shaft, in particular according to any one of Claims 1 to 7, characterized by at least two of the steps mentioned below before or after the fitting or depression of the bushing ( 7) on the shaft by means of the interlocking connection (5, 6). a) turning a part inside the one-piece profile with the shaft profile b) making a groove in the outer end zone of the profile, c) making a chamfer at beginning of the inner contour in the profile area, d) making a clearance groove in the end zone of the cylindrical inner contour in the profile area.   9. hollow shaft according to claim, characterized in that a heat treatment, in particular a softening annealing, occurs between certain steps, preferably between steps d) and e).